A foul odor in the vagina is usually seen in bacterial vaginitis. Bacterial vaginitis is caused by bacterial imbalance, the vaginal beneficial bacteria lactobacillus decreased, Gardnerella, anaerobic bacteria relatively high, anaerobic bacteria increase will produce a kind of amine substances, such as cadaverine, putrescine, trimethylamine, etc., amine substances emit a kind of fishy odor, for the vagina has a fishy odor is a typical feature of bacterial vaginitis. For treatment, you can use Ding Junsheng treatment, but also with the application of metronidazole drugs, local vaginal metronidazole suppositories, oral metronidazole tablets. At the same time, we should pay attention to the cleanliness and hygiene of the vulva, change underwear and panties, and try to wear loose cotton underwear.